My program is supposed to take the two middle values of a word, in this case "es". I used a second variable to get "s" as the program would already collect "e" however, when I run this program the values returned are integers instead of letters.
using System;
using System.Linq;
class Program
{
public static void Main(string[] args)
{
string word = "Test";
int wordLength = word.Count();
if (wordLength % 2 == 0)
{
int middle = word[wordLength / 2];
int nextAlong = middle + 1;
Console.WriteLine("Even number");
Console.WriteLine("{0},{1}", middle, nextAlong);
}
else
{
Console.WriteLine("Odd number");
Console.WriteLine(word[wordLength / 2]);
}
}
}
The console output is
Even number
115,116
Indexing into a string does return a char but because you’ve defined the middle and nextAlong variables as being of type int, they’re getting implicitly converted from char to int.
Try the following instead.
public static void Main( )
{
string word = "Test";
int wordLength = word.Length;
if (wordLength % 2 == 0)
{
var middleIndex = wordLength / 2 - 1;
char middle = word[middleIndex];
char nextAlong = word[middleIndex + 1];
Console.WriteLine("Even number");
Console.WriteLine($"{middle},{nextAlong}");
}
else
{
Console.WriteLine("Odd number");
Console.WriteLine(word[wordLength / 2]);
}
}
Related
so we can give any number of parameters to a method, like this:
static int sumPrices(params int[] prices) {
int sum = 0;
for (int i = 0; i < prices.Length; i++) {
sum += prices[i];
}
return sum;
}
static void Main(string[] args)
{
int total = sumPrices(100, 50, 200, 350);
Console.WriteLine(total);
Console.ReadKey();
}
but ... what if we wanted to get the "100, 50, 200, 350" from the USER?
in above example it's the coder giving the sumPrices method its arguments/parameters.
i mean, it would be one solution to just pass the method an array.
static int sumPrices(int[] prices) {
int sum = 0;
for (int i = 0; i < prices.Length; i++) {
sum += prices[i];
}
return sum;
}
static void Main(string[] args)
{
//get up to 9999 inputs and sum them using a method
bool whileLoop = true;
int[] inputs = new int[9999];
int index = 0;
while (whileLoop == true)
{
Console.WriteLine("entering price #" + index + ", type 'stop' to sum prices");
string check = Console.ReadLine();
if (check == "stop") {
whileLoop = false;
break;
}
inputs[index] = int.Parse(check);
index++;
}
int[] prices = new int[index];
for (int i = 0; i < index; i++)
{
prices[i] = inputs[i];
}
Console.WriteLine("-----------------");
Console.WriteLine(sumPrices(prices));
Console.ReadKey();
}
BUT... longer code... and has limits.
our professor basically wanted the first code, however, i don't see how and where it's
supposed be used if we didn't know the user's inputs and if params arguments were coming from the coder (unless of course, coder using the same function multiple times for convenience)
i have tried to think of a solution and i'm not exactly sure how it could be done.
but it basically goes like this.
we could get inputs from the user separated by commas:
100,200,50
and the program would translate it into params arguments:
sumPrices("100,200,50");
but as you can see... it's a string. i wonder if there's a JSON.parse() thing like in js.
The code in the OP has some unnecessary code as well as some limitations such as 9999.
Let's examine the following code:
bool whileLoop = true;
while (whileLoop == true)
{
}
This could be re-written as:
while (true == true)
{
}
or
while (true)
{
}
Next, let's examine the following code:
if (check == "stop") {
whileLoop = false;
break;
}
You've set whileLoop = false; which is unnecessary because once break is executed, excution has moved to after the loop.
Since the input array has a hard-code size of 9999, you've limited yourself to 9999 values. You may consider using a List instead or resize the array.
Try the following:
using System;
using System.Collections.Generic;
using System.Linq;
namespace UserInputTest
{
internal class Program
{
static void Main(string[] args)
{
decimal price = 0;
List<decimal> _values = new List<decimal>();
if (args.Length == 0)
{
//prompts for user input
Console.WriteLine("The following program will sum the prices that are entered. To exit, type 'q'");
do
{
Console.Write("Please enter a price: ");
string userInput = Console.ReadLine();
if (userInput.ToLower() == "q")
break; //exit loop
else if (Decimal.TryParse(userInput, out price))
_values.Add(price); //if the user input can be converted to a decimal, add it to the list
else
Console.WriteLine($"Error: Invalid price ('{userInput}'). Please try again.");
} while (true);
}
else
{
//reads input from command-line arguments instead of prompting for user input
foreach (string arg in args)
{
if (Decimal.TryParse(arg, out price))
{
//if the user input can be converted to a decimal, add it to the list
_values.Add(price); //add
}
else
{
Console.WriteLine($"Error: Invalid price ('{arg}'). Exiting.");
Environment.Exit(-1);
}
}
}
Console.WriteLine($"\nThe sum is: {SumPrices(_values)}");
}
static decimal SumPrices(List<decimal> prices)
{
return prices.Sum(x => x);
}
static decimal SumPricesF(List<decimal> prices)
{
decimal sum = 0;
foreach (decimal price in prices)
sum += price;
return sum;
}
}
}
Usage 1:
UserInputTest.exe
Usage 2:
UserInputTest.exe 1 2 3 4 5
Resources:
Built-in types (C# reference)
Floating-point numeric types (C# reference)
Decimal.TryParse
Iteration statements - for, foreach, do, and while
String interpolation using $
List Class
Enumerable.Sum Method
Default values of C# types (C# reference)
Environment.Exit
The trick is input from the user always starts out as strings. You must parse those strings into integers. We can do it in very little code like this:
static int sumPrices(IEnumerable<int> prices)
{
return prices.Sum();
}
static void Main(string[] args)
{
int total = sumPrices(args.Select(int.Parse));
Console.WriteLine(total);
Console.ReadKey();
}
See it here (with adjustments for the sandbox environment):
https://dotnetfiddle.net/Pv6B6e
Note this assumes a perfect typist. There is no error checking if a provided value will not parse.
But I doubt using linq operations are expected in an early school project, so we can expand this a little bit to only use techniques that are more familiar:
static int sumPrices(int[] prices)
{
int total = 0;
foreach(int price in prices)
{
total += price;
}
return total;
}
static void Main(string[] args)
{
int[] prices = new int[args.Length];
for(int i = 0; i<args.Length; i++)
{
prices[i] = int.Parse(args[i]);
}
int total = sumPrices(prices);
Console.WriteLine(total);
Console.ReadKey();
}
If you're also not allowed to use int.Parse() (which is nuts, but sometimes homework has odd constraints) you would keep everything else the same, but replace int.Parse() with your own ParseInt() method:
static int ParseInt(string input)
{
int exponent = 0;
int result = 0;
for(int i = input.Length -1; i>=0; i--)
{
result += ((int)(input[i]-'0') * (int)Math.Pow(10, exponent));
exponent++;
}
return result;
}
Again: there's no error checking here for things like out-of-bounds or non-numeric inputs, and this particular implementation only works for positive integers.
Task:
The program asks the user to enter the text, after entering the text, the program declares how many words are in the text. It also counts the amount of digits in the text and displays it on the screen.
static void Main(string[] args)
{
Console.Write("Insert text: ");
string s = Console.ReadLine();
int count = 1, num, sum = 0, r;
for (int i = 1; i < s.Length; i++)
{
if (Char.IsWhiteSpace(s[i]))
{
count++;
}
}
num = int.Parse(Console.ReadLine());
while (num != 0)
{
r = num % 10;
num = num / 10;
sum = sum + r;
}
Console.WriteLine("Sum of Digits of the Number : " + sum);
Console.WriteLine("In text {1} names", s, count);
}
The program asks for the text and numbers to be entered. The numbers in the text are counted why doesnt it work correctly?
As per the input/output described in the comment, You do not need a second ReadLine Statement. You can do as follows.
static void Main(string[] args)
{
Console.WriteLine("Enter Text");
var userEntry = Console.ReadLine();
var countOfWords = userEntry.Split(new []{" "},StringSplitOptions.RemoveEmptyEntries).Count();
var sum = userEntry.Where(c => Char.IsDigit(c)).Select(x=>int.Parse(x.ToString())).Sum();
Console.WriteLine($"Count Of Words :{countOfWords}{Environment.NewLine}Sum :{sum}");
}
This is in the case when(as per your comment), the input string is "xsad8 dlas8 dsao9", for which the sum would be 25.
If the input string is "xsad8 dlas81 dsao9" and you want to treat 81 as '81', rather than 8 & 1, the Sum can be calculated as follows.
var sum = Regex.Split(userEntry, #"\D+").Where(s => s != String.Empty).Sum(x=>int.Parse(x));
Sum in above case would be 98
Try this code. I hope it will help you.
using System;
namespace SimpleProblem
{
class Program
{
static void Main(string[] args)
{
// Task:
// The program asks the user to enter the text, after
// entering the text, the program declares how many words
// are in the text. It also counts the amount of digits in
// the text and displays it on the screen.
Console.WriteLine("Enter a Text");
string word = Console.ReadLine();
int wordCount = 0;
char[] wordsArray = word.ToCharArray();
foreach (var item in wordsArray)
{
//Counting the number of words in array.
wordCount = wordCount + 1;
}
Console.WriteLine("Entered Text: " + word);
Console.WriteLine("No. of Counts: " + wordCount);
}
}
}
I am trying to get input from user 5 times and add those values to marks array;
Then, it will calculate the average and print positive or negative accordingly. However, I can not take input from the user it just prints "Enter 5 elements". After getting input from user how can I add them to marks array? Any tips would be helpful.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;
class Program
{
static void Main()
{
double average =0;
int [] marks = new int[] { };
for (int a = 0; a < 5; a++){
Console.WriteLine("Enter 5 elements:");
string line = Console.ReadLine();
Console.WriteLine(line);
}
for (int i = 0; i < marks.Length; i++){
average = marks.Average();
}
if(average>0){
Console.WriteLine("Positive");
}else{
Console.WriteLine("Negative");
}
}
}
I would use a while loop combined with int.TryParse to check if the user input is a number. Also it doesn't make any sense to put average = marks.Average(); inside a for loop, because LINQ Average calculates the average of a collection (in your case the marks array).
static void Main()
{
int[] marks = new int[5];
int a = 0;
Console.WriteLine("Enter 5 elements:");
while (a < 5)
{
if (int.TryParse(Console.ReadLine(), out marks[a]))
a++;
else
Console.WriteLine("You didn't enter a number! Please enter again!");
}
double average = marks.Average();
if (average > 0)
Console.WriteLine("Positive");
else
Console.WriteLine("Negative");
}
DEMO HERE
Edited my answer to illustrate solving your problem without a for loop.
class Program
{
const int numberOfMarks = 5;
static void Main()
{
List<int> marks = new List<int>();
Enumerable.Range(1, numberOfMarks)
.ForEach((i) => {
Console.Write($"Enter element {i}:");
marks.Add(int.TryParse(Console.ReadLine(), out var valueRead) ? valueRead : 0);
Console.WriteLine($" {valueRead}");
});
Console.WriteLine(marks.Average() >= 0 ? "Positive" : "Negative");
}
}
This will help you, just copy and paste it.
There are some explanation with comments.
class Program
{
static void Main()
{
const int numberOfMarks = 5;
int[] marks = new int[numberOfMarks];
Console.WriteLine("Enter 5 elements:");
for (int a = 0; a < numberOfMarks; a++)
{
// If entered character not a number, give a chance to try again till number not entered
while(!int.TryParse(Console.ReadLine(), out marks[a]))
{
Console.WriteLine("Entered not a character");
}
Console.WriteLine("You entered : " + marks[a]);
}
// Have to call Average only once.
var avg = marks.Average();
Console.WriteLine(avg > 0 ? "Positive average" : "Negative average");
Console.ReadLine();
}
}
Follow Stackoverflow Answer
since integer array is being used, and as input from the console is a string value, you need to convert it using Parse() Method. For e.g.
string words = "83";
int number = int.Parse(words);
Edit: using string variable in parsing.
My code finds prime numbers in a given range. I want to make a menu in the end of it that will ask if i want to save output numbers to a file and then save it. I would really appreciate any help.
using System;
public class Exercise34
{
public static void Main()
{
int num,i,ctr,stno,enno;
Console.Write("\n\n");
Console.Write("Find the prime numbers within a range of numbers:\n");
Console.Write("---------------------------------------------------");
Console.Write("\n\n");
Console.Write("Input starting number of range: ");
stno = Convert.ToInt32(Console.ReadLine());
Console.Write("Input ending number of range : ");
enno = Convert.ToInt32(Console.ReadLine());
Console.Write("The prime numbers between {0} and {1} are : \n",stno,enno);
for(num = stno;num<=enno;num++)
{
ctr = 0;
for(i=2;i<=num/2;i++)
{
if(num%i==0){
ctr++;
break;
}
}
if(ctr==0 && num!= 1)
Console.Write("{0} ",num);
}
Console.Write("\n");
}
}
I suggest extracting method(s): do not cram everything into single Main, decompose the solution into easy to read and debug routines
private static bool IsPrime(int value) {
if (value <= 1)
return false;
if (value % 2 == 0)
return value == 2;
int n = (int) (Math.Sqrt(value) + 0.5);
for (int i = 3; i <= n; i += 2)
if (value % i == 0)
return false;
}
private static IEnumerable<int> Primes(int from, int to) {
if (to <= 1)
yield break;
if (from < 2)
from = 2;
for (int value = from; value <= to; ++value)
if (IsPrime(value))
yield return value;
}
And then you put it as simple as (output to Console)
public static void Main() {
...
Console.Write("The prime numbers between {0} and {1} are : \n",stno,enno);
foreach (int value in Primes(stno, enno))
Console.WriteLine(value);
}
or (output to File)
using System.IO;
using System.Linq;
...
public static void Main() {
...
Console.Write("The prime numbers between {0} and {1} are : \n",stno,enno);
File.WriteAllLines(#"c:\MyFile.txt", Primes(stno, enno)
.Select(value => value.ToString()));
}
i know how to make a console read two integers but each integer by it self like this
int a = int.Parse(Console.ReadLine());
int b = int.Parse(Console.ReadLine());
if i entered two numbers, i.e (1 2), the value (1 2), cant be parse to integers
what i want is if i entered 1 2 then it will take it as two integers
One option would be to accept a single line of input as a string and then process it.
For example:
//Read line, and split it by whitespace into an array of strings
string[] tokens = Console.ReadLine().Split();
//Parse element 0
int a = int.Parse(tokens[0]);
//Parse element 1
int b = int.Parse(tokens[1]);
One issue with this approach is that it will fail (by throwing an IndexOutOfRangeException/ FormatException) if the user does not enter the text in the expected format. If this is possible, you will have to validate the input.
For example, with regular expressions:
string line = Console.ReadLine();
// If the line consists of a sequence of digits, followed by whitespaces,
// followed by another sequence of digits (doesn't handle overflows)
if(new Regex(#"^\d+\s+\d+$").IsMatch(line))
{
... // Valid: process input
}
else
{
... // Invalid input
}
Alternatively:
Verify that the input splits into exactly 2 strings.
Use int.TryParse to attempt to parse the strings into numbers.
You need something like (no error-checking code)
var ints = Console
.ReadLine()
.Split()
.Select(int.Parse);
This reads a line, splits on whitespace and parses the split strings as integers. Of course in reality you would want to check if the entered strings are in fact valid integers (int.TryParse).
Then you should first store it in a string and then split it using the space as token.
Read the line into a string, split the string, and then parse the elements. A simple version (which needs to have error checking added to it) would be:
string s = Console.ReadLine();
string[] values = s.Split(' ');
int a = int.Parse(values[0]);
int b = int.Parse(values[1]);
string[] values = Console.ReadLine().Split(' ');
int x = int.Parse(values[0]);
int y = int.Parse(values[1]);
in 1 line, thanks to LinQ and regular expression (no type-checking neeeded)
var numbers = from Match number in new Regex(#"\d+").Matches(Console.ReadLine())
select int.Parse(number.Value);
string x;
int m;
int n;
Console.WriteLine("Enter two no's seperated by space: ");
x = Console.ReadLine();
m = Convert.ToInt32(x.Split(' ')[0]);
n = Convert.ToInt32(x.Split(' ')[1]);
Console.WriteLine("" + m + " " + n);
This Should work as per your need!
public static class ConsoleInput
{
public static IEnumerable<int> ReadInts()
{
return SplitInput(Console.ReadLine()).Select(int.Parse);
}
private static IEnumerable<string> SplitInput(string input)
{
return Regex.Split(input, #"\s+")
.Where(x => !string.IsNullOrWhiteSpace(x));
}
}
int a, b;
string line = Console.ReadLine();
string[] numbers= line.Split(' ');
a = int.Parse(numbers[0]);
b = int.Parse(numbers[1]);
Try this:
string numbers= Console.ReadLine();
string[] myNumbers = numbers.Split(' ');
int[] myInts = new int[myNumbers.Length];
for (int i = 0; i<myInts.Length; i++)
{
string myString=myNumbers[i].Trim();
myInts[i] = int.Parse(myString);
}
Hope it helps:)
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace SortInSubSet
{
class Program
{
static int N, K;
static Dictionary<int, int> dicElements = new Dictionary<int, int>();
static void Main(string[] args)
{
while (!ReadNK())
{
Console.WriteLine("***************** PLEASE RETRY*********************");
}
var sortedDict = from entry in dicElements orderby entry.Key/3 , entry.Value ascending select entry.Value;
foreach (int ele in sortedDict)
{
Console.Write(ele.ToString() + " ");
}
Console.ReadKey();
}
static bool ReadNK()
{
dicElements = new Dictionary<int, int>();
Console.WriteLine("Please entere the No. of element 'N' ( Between 2 and 9999) and Subset Size 'K' Separated by space.");
string[] NK = Console.ReadLine().Split();
if (NK.Length != 2)
{
Console.WriteLine("Please enter N and K values correctly.");
return false;
}
if (int.TryParse(NK[0], out N))
{
if (N < 2 || N > 9999)
{
Console.WriteLine("Value of 'N' Should be Between 2 and 9999.");
return false;
}
}
else
{
Console.WriteLine("Invalid number: Value of 'N' Should be greater than 1 and lessthan 10000.");
return false;
}
if (int.TryParse(NK[1], out K))
{
Console.WriteLine("Enter all elements Separated by space.");
string[] kElements = Console.ReadLine().Split();
for (int i = 0; i < kElements.Length; i++)
{
int ele;
if (int.TryParse(kElements[i], out ele))
{
if (ele < -99999 || ele > 99999)
{
Console.WriteLine("Invalid Range( " + kElements[i] + "): Element value should be Between -99999 and 99999.");
return false;
}
dicElements.Add(i, ele);
}
else
{
Console.WriteLine("Invalid number( " + kElements[i] + "): Element value should be Between -99999 and 99999.");
return false;
}
}
}
else
{
Console.WriteLine(" Invalid number ,Value of 'K'.");
return false;
}
return true;
}
}
}
I have a much simpler solution, use a switch statement and write a message for the user in each case, using the Console.write() starting with a ("\n").
Here's an example of filling out an array with a for loop while taking user input. * Note: that you don't need to write a for loop for this to work*
Try this example with an integer array called arrayOfNumbers[] and a temp integer variable. Run this code in a separate console application and Watch how you can take user input on the same line!
int temp=0;
int[] arrayOfNumbers = new int[5];
for (int i = 0; i < arrayOfNumbers.Length; i++)
{
switch (i + 1)
{
case 1:
Console.Write("\nEnter First number: ");
//notice the "\n" at the start of the string
break;
case 2:
Console.Write("\nEnter Second number: ");
break;
case 3:
Console.Write("\nEnter Third number: ");
break;
case 4:
Console.Write("\nEnter Fourth number: ");
break;
case 5:
Console.Write("\nEnter Fifth number: ");
break;
} // end of switch
temp = Int32.Parse(Console.ReadLine()); // convert
arrayOfNumbers[i] = temp; // filling the array
}// end of for loop
The magic trick here is that you're fooling the console application, the secret is that you're taking user input on the same line you're writing your prompt message on. (message=>"Enter First Number: ")
This makes user input look like is being inserted on the same line. I admit it's a bit primitive but it does what you need without having to waste your time with complicated code for a such a simple task.